1. Field of the Invention
This invention concerns an instrument for measuring the protection afforded by a corrosion inhibiting material. More specifically, it deals with an electrical measuring instrument that can measure the effectiveness of a corrosion inhibitor by determining the electrical resistance of the film that is created by such inhibitor, in a corroding system.
2. Description of the Prior Art
While there is known laboratory instrumentation which is capable of making measurements comparable to those desired by this invention, such instrumentation is relatively complex and delicate and quite expensive. Furthermore, such instrumentation is not readily usable in general field use, which is where the desired measurements would be taken.
Heretofore, there have been some suggestions for making measurements in order to determine the resistance of fluids, e.g. gasoline, in case water content is suspected. But, the arrangement proposed in that case dealt with measurements of the current flow through the fluid directly. And, particular measures were taken to avoid any polarization or electrolysis which might tend to cause surface effects and so change the impedance of the fluid. Consequently, that proposal failed to recognize, or in any way suggest something in accordance with this invention. A patent which disclosed a system of the foregoing type is U.S. Pat. No. 3,909,709, issued Sept. 30, 1975 to Leroy J. Maxon.
Thus, it is an object of this invention to provide a relatively inexpensive and simple, yet highly accurate and useful method and apparatus for measuring the effectiveness of a corrosion inhibitor, especially where the inhibition is created by a film on the surface which would tend to corrode.